High Range problem, HELP

[artica5105]

Haven't seen an update recently and was wondering if you gave up. Hopefully not. Since you've no doubt checked the linkage several times, I think NDT is on to something about checking the internals of the reduction control valve. You also said Tom was mentioning checking for rust and you said it looked clean. I'm thinking there may be a possibility that if rust had formed while the truck was unused and when it was again started, some of the freed rust particles circulated through the system and may be causing the reduction valuing to bind. Did the truck sit unused long enough to allow water vapor to form, from the daily changes in ambient temperature, which could eventually lead to surface rust of the internals?

Keep in mind I'm not a pro like some of the other members here, but thought I'd throw out this possibility. If nothing else it may keep you from giving up.


Christian

 

[white135]

Not to hijack the thread, but I am having a similar problem.

Everything works fine in low range including the shift from/to high, however it does not go in High.

While going down a slope in low range, I tried the shift into high trick as mentioned before. I shifted to high neutral and there was a clunk, then into f-2 high and It went into high for a distance, before I had to stop.

Since then, When going into high from a stop, it still does nothing, but trying while moving, even into high neutral, locks the back axles and the front pulls a little before I stop.

I was hoping for some advice before I break something...

Thanks
Eric

 

[white135]

Not to harass or anything, but I was wondering if anyone had a theory about this specific problem.

I have very limited time/opportunity to work on the truck, and was hoping someone had had this problem.

I will probably try to pull the reduction valve on my next trip, but it seems odd that it suddenly locks up the rear axles...

TIA

Eric

 

[BugEyeBear]

Not to harass or anything, but I was wondering if anyone had a theory about this specific problem.

I have very limited time/opportunity to work on the truck, and was hoping someone had had this problem.

I will probably try to pull the reduction valve on my next trip, but it seems odd that it suddenly locks up the rear axles...

TIA

Eric

Eric,

Suggest you send a PM to MajorTom (or call him, see earlier post in this thread for #). He has a lot of experience w these old Dueces.

OR perhaps you could call Alpha Heaven or Memphis Equipment to see if they have any ideas. Memphis used to rebuild these trannies (they don't anymore) & they might be familiar w your symptoms. OR maybe one of these can at least point you to someone (a repair facility or a seasoned owner) who can help!

-Bear-

 

[artica5105]

Not to harass or anything, but I was wondering if anyone had a theory about this specific problem.

I have very limited time/opportunity to work on the truck, and was hoping someone had had this problem.

I will probably try to pull the reduction valve on my next trip, but it seems odd that it suddenly locks up the rear axles...

TIA

Eric

I may be missing the jist of some of your testing descriptions, but it seems to me the problem could be in the transfer case, maybe the linkage to the front driveshaft sprag gears.

The fronts should only "pull" when the rear wheels slip. You can test this by jacking up one of the front tires and spinning it by hand. No need to have the truck running for this. With the transmission in drive the tire should spin freely in one direction, but bind the other. When the transmission is placed in reverse the tire should spin freely the opposite direction of the first test. Remember all of this testing is with the engine off. I wish I could remember which way they should freewheel in the selected drive range, but I can't.

My only other thought is that the driveline is bound up enough to prevent movement in high, but with the extra torque in low range it can overcome this.
I don't see this happening in the transmission or reduction unit.

Hope some of this helps.

 

[Brad]

M135 help ?

Hello again friends.
I again call upon you folks for some advise.
We still have no results in high range.
Everything works fine in low range.
I have tried every suggestion I am able to try.
We removed the wavy washer, it was not broken.
We tooke the clutch pack aoaprt. It was not rusty and is like new inside.
We have flushed the entire transmission with 10w oil and MArvells mystery oil.
There is no rust inside.
We have disconnected the high low linkage and tried that.
I do not have a pressure gauge to check that . But the fact that it works fine in low range, I am told that the actual transmission is working?
When I shift into the high range side just nothing happens?
Does anyone know of a place that works on these trucks, say east of Pittsburgh?? We are about 60 miles due east of Pittsburgh.
I really need to get this working for my Dad. I just dont know what to do next??
Thanks so much,
Brad Foust

 

[badgmc56]

If you want to diagnose this trans problem, you MUST check the oil pressures in high and low range. That will lead you in the right direction. When my trans had problems, I went on e-bay and bought one for 40.00. You also need to get the trans manual that I mentioned in my last post on this subject. Was the piston and seal in good shape when you pulled the clutch pack apart? My piston seal was blown right out and had no high range.

 

[Brad]

high range problem continues

Friends,
First of all I want to thank everyone for there help and suggestions.
Unfortunatley, still no high range.
Please let me review all I have tried.
We took the reduction unit off hoping to find a broken wavy washer spring.
But it was not broken.
There was ever the slightest amount of surface rust on one of the cones so we took that clutch pack apart hoping to find it, or not hoping? that it would be rusty.
But it was like new inside, no rust no signs of wear.
This truck is almost like new inside.
We put it all back together and since we already had the 10W ND motor oil we thought was correct my father insisted we put that back in along with a gallon of Marvells Mystery Oil, only to try it with and to flush it clean in case there is anything in there.
It is so clean you can almost not see it on the dip stick.
Well, it works just fine in low range, but nothing in high range.
Last night I removed the linkage and wired it tight in the high range position, but nothing at all. Still no higfh range.
I am wondering, does that 10 weight motoer oil foam?? Would that be the problem?
The only thing I have not yet tried, I dont have a gauge, is to check the pressure in the tranny. But others here have told me that since the tranny works fine in low range, that would not be the problem?
Does anyone know of any mechanics in the area east of Pittsburgh that is knowledgable on these things.
I like working on this stuff but I know when I am whipped.
And I have to get this up and going for my Dad. He will be 80 next week.
Any and all help is greatly appreciated.
Thanks so much,
Brad Foust

 

[badgmc56]

If someone told you the pressures are the same in low and high range, they are mistaken! Just because it has low range , it does not mean the pressures are ok in high range. Trust me when I tell you I went back and forth with this same problem. I checked the pressures and it led me to a bad piston seal behind the clutch pack.If that seal is blown out, the pressue will not be normal. That piston compresses the clutch pack for high range.

 

[butch atkins]

Brad,please get someone to download the manuals from this site,TM 9-8025-2 Hydramatic Transmissions,TM 9-8024,Operation have to get me son to do this for me,computer illiterate i am. Straight from the manual,Oil Press. Limits, 1,in both hi/lo there must not be more than a 30 psi drop in press between neutral & drive at idle, 2, Oil press in N (400 rpm),MUST NOT drop more than 5 psi from H to L, 3, same as #2 except opposite,from L to Hi. ,if the clutches are good the pistons have to be leaking or the clutch paks would close up and engage,also posiible this ,from TM 9-8024,Reduction Unit & RED Unit Control Valve,faulty Red unit parts contribute to 1-5. 1,drives only in low, 2,drives only in Hi, 3, shift can be made from H to L at improper engine speed, 4, Will Not respond when shifted from H to L or vice versa, 5 , slips in all speeds, hopr this helps ,if you can get any kind of guage that will check liquid pressure up to 300 psi ,you can do this yourself with the manuals,the max pressure the tranny puts out is 220 psi in reverse,normal press in both H/L at 375 rpm is 75 to 110 psi,the tranny manual has a pic of the gage,you can do this,get the manuals,check pressure and you can go from there,good luck

 

[Brad]

Tahnks everyone,
Even if I never get this thing going I am meeting some great people in the process.
I am going to try and download that manual.
In the mean time, exactly what kind of pressure gauge do I need?
Can I buy this at an auto store?
When I had that clutch pack torn apart I wanted to remove that geat cluster and look at the piston. My Dad didnt want to, so.. well you know.
Anyway. I was able to pretty easily reach back behind the gears with a screwdriver and work that piston in and out close to an ince.
Maybe it being so loose is a sign of a bad seal?
At the time I was glad to see it wasnt froze up. But perhaps it was actually too sloppy?
I guess its back under the truck for a weekend.
Thanks again,
Brad

 

[Brad]

high range problem, continued

Well folks looks like we are at the end of the line with this high range problem.
It just will not do anything in high range, though it works fine in low range.
Have tried all suggestions, thanks but no luck.
Just now tried getting it going as fast as possible in low and then crossing over to high.
It slides the wheels but that all. Tried that 8 or 10 times and no change.
Dad has all the parts here in another truck to change it over to standard tranny. He is determined to do that. I wish I could just get it going as is. This truck has never been butchered up and is so nice and original it would be a shame to change it.
Any last suggetions?
Does anyone know of anyone in the western Pa area that might be available to fix this thing?
Thanks,
Brad Foust

 

[hippiedude]

Try to find another auto trany for it ...I bet someone on this site has one in a parts truck ......... Put up a want add in the classifieds ........Good luck ........... Tim

 

[chicklin]

I suppose you've already got it changed over to the manual, but did you ever check the fluid pressure on this thing? I realize you were probably pretty frustrated, but that is a pretty important troubleshooting step.